chemistry question??

Question

how do u tell if a substance is aqueous or solid, suppose BaCO3 what is it? (s) or (aq)? and whats AgNO3?

Answer 1

Well, it depends on whether the substance can dissolve in water. Generally, for ionic compounds, here are a few rules:
All nitrates are soluble.
All chlorides are soluble except for AgCl and lead (II) chloride (which is only soluble in hot water).
All sulphates are soluble except barium sulphate, lead (II) sulphate and calcium sulphate (slightly soluble).
All carbonates are insoluble EXCEPT sodium carbonate, potassium carbonate and ammonium carbonate.
All compounds of sodium, potassium and ammonium are soluble.

Thus barium carbonate is insoluble, (s). Silver nitrate, AgNO3, is soluble, (aq).
Silver nitrate solution, acidified with sulphuric acid, is usually used in lab to test for presence of chloride ions. Formation of a white ppt of silver chloride indicates presence of chloride ions.
Hope this helps. :)

Answer 2

aqueous means that the compound has been placed in water and the ions have dissociated. so when a problem says that a soluble compound is placed in water, then it is (aq). that is to say, a compound doesn't just exist as (aq), it has to be physically placed in water for it to be aqueous.

now the question is what compounds are actually soluble? this website gives you some helpful rules.
http://www.csudh.edu/oliver/chemdata/solrules.htm

AgNO3 is soluble so when placed in water, it will dissociate into Ag+ and NO3-. This means that when placed in water, it becomes AgNO3(aq)

BaCO3 is insoluble so when placed in water, it will stay a solid, BaCO3(s)

Answer 3

The word aqueous is derived from AQUA...meaning water. Aquesous means solution in water. SO BaCO3 (barium carbonate) is salt. Auqeous BaCO3 means solution of BaCO3 in water. AgNO3 is silver nitrate. Itr is solid but can be dissolved in water to make an aqueous solution.